Comtech EF Data SDM-2020, Installation And Operation Manual

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Operation SDM-2020 Satellite Demodulator
3–54 Rev. 3
3.4.1 (C+N)/N to C/N and E
b
/N
0
Conversion
Table 3-5 provides conversions from (C+N)/N to Eb/N0 that are useful when evaluating
satellite links with a spectrum analyzer.
The following equations was used to build the conversion table.
C/N (= Co/No) = 10*Log(10^[(C+N)/N/10]-1)
and Eb/No
= C/N – 10*Log(m*CRv) – 10*Log(188/204)
Modulation Inner Code Eb/N0 = C/N +
QPSK ½ 0.35
QPSK 2/3 -0.89
QPSK ¾ -1.41
QPSK 5/6 -1.86
QPSK 7/8 -2.08
8PSK 2/3 -2.66
8PSK 5/6 -3.62
8PSK 8/9 -3.90
16QAM ¾ -4.42
16QAM 7/8 -5.09